Firing device

ABSTRACT

A firing device having an anti-disturbance firing mechanism; a lead short, shunt, or open circuit firing mechanism; and an operator actuated switch firing mechanism, wherein each of said firing mechanisms is capable of causing detonation of a squib. The power supply and the operator actuated arm/disarm and firing switch and ready lamp are included in a control unit remote from the squib housing.

United States Patent [1 1 Swallow et a1.

3, 750,586 Aug, 7, 1973 FIRING DEVICE Inventors: Robert E. Swnilow;Darrell A.

Bymoen; Gnyllon L. Went, all of China Lake, Calif.

The United States 011' Americn as represented by the Secretory oi theNavy, Washington, DC.

Filed: June 25, 1071 Appl. N0.: 156,679

Assignee:

US. Cl 102/16, 102/192, 102/702 R Int. Cl. F421) 23/26, F42b 21/38 Fieldof Search 102/8, 16, 18, 19.2,

References Cited UNITED STATES PATENTS West et a1. H 102/702 R West102/192 Primary Examiner-Benjamin A. Borchelt Assistant Examiner.lamesM. Hanley Atmrney- R. S. Sciascia, Roy Miller ct a1.

[5 7] ABSTRACT A firing device having an anti-disturbance firingmechanism; a lead short, shunt, or open circuit firing mechanism; and anoperator actuated switch firing mechanism, wherein each of said firingmechanisms is capable of causing detonation of a squib. The power supplyand the operator actuated arm/disarm and firing switch and ready lampare included in a control unit remote from the squib housing.

3 Claims, 2 Drawing Figures R5; Q2 R? as I i I I I I I I B I I I I I ISQLJIB DETONATING CIRCUIT PATENIED AUG 7 I975 same or 2 u oun MW MwN T mmm nHmo WE N0 M W0. m m I I I I I I I I I I I II IIIL FIRING DEVICEBACKGROUND OF THE INVENTION In certain mines and land mines in which thefiring mechanism is positioned at a remote location from the squib andmine, the enemy has conceived plans and prescribed procedures whichcompromise the explosive device. Therefore, until now a need has existedfor such a device which is uncompromiseable, but disarmable. The presentinvention fulfills that need.

SUMMARY OF THE INVENTION The present invention is a remotely actuable,uncompromiseable, but disarmable, firing device. It consists of aremotely located, control unit coupled to a squib and squib detonatingcircuit located at the explosive device. The control unit includes anarm/disarm switch, an operator actuated firing switch, and a ready lamp.The squib detonating circuit includes a firing capacitor, ananti-disturbance firing mechanism, and a silicon controlled rectifier(SCR) with associated passive components.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a block diagram of thepresent invention; and

FIG. 2 is a schematic diagram of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention is shownin block diagram form in FIG. I It includes a power supply M, a remotecontrol unit 10, a squib detonating circuit 12, and a squib 28. Theremote control unit 10 comprises an arm/disarm switch 16 coupled to thepower supply 14, a ready lamp circuit 18 coupled to switch 16, and anoperator actuated firing switch 20 coupled to circuit 18. Remote controlunit 10 is coupled through long lead coupler 22 to squib detonatingcircuit 12. The squib detonating circuit comprises anti-disturbancefiring mechanism 24 and firing circuit 26. Squib 28 is coupled to theoutput of firing circuit 26.

The schematic diagram of the preferred embodiment of the presentinvention is shown in FIG. 2, wherein like numerals are used to indicatethe component composition of the blocks of FIG. 1. Remote control unit 1taken alone, includes lamp L, connected in series with resistor R, tothe collector, and in parallel with the operator actuated firing switch20 connected between the lamp and base, of NPN transistor 0,; and thecombination coupled in parallel with capacitor C, to arm/- disarm switch16. Of course, transistor Q, can be replaced with a PNP transistor ifthe circuit is appropriately modified, as is well known in the art.

Squib detonating circuit 12 comprises antidisturbance firing mechanism24 and firing circuit 26. Firing circuit 26, taken alone, includesresistor R coupled to the gate of silicon controlled rectifier (SCR) 0which, in combination with anti-disturbance firing mechanism 24, diodeD,, resistor R and capacitor C is serially connected to the parallelcombination of capacitor C and resistor R Squib detonating circuit 12 iscoupled to remote control unit by double lead'line coupler 22.

While applicant does not wish to be limited to any particular set ofcircuit constants, the following constant has proven to be useful in theparticular circuit shown.

Symbol Components Type or Value 14 Battery 45 volt NEDA 2l3 C, Capacitormicrofarads, 50 volt R, Resistor l Kilohm Q, Transistor 2N3904 R,Resistor l Kilohm R, Resistor l0 Kilohm R Resistor 220 Kilohm D, DiodelN9l6 C, Capacitor 2200 Picofarad R Resistor l Kilohm Q Siliconcontrolled 2N885 rectifier R Resistor 470 Kilohm C Capacitor 5Omicrofarad, 50 volt For the above indicated components the operation isas follows: When arm/disarm switch 16 is closed current from powersupply 14 charges capacitors C, and C Lamp L, will light if there is acompleted circuit, and then, will turn off when the circuit is ready tofire, i.e., when G, is sufficiently charged. Squib 28 will then detonateif any of the following occurs: (a) squib detonating circuit 12 isdisturbed causing anti-disturbance firing mechanism 24 to close, (bl thelong leads connected to coupler 22 are shorted, shunted, or opencircuited, or (c) operator actuated firing switch 20 is closed. All ofthe firing actions caused the voltage difference between points A and Bto approach zero, which causes silicon controlled rectifier O to turn onand conduct. Thereby, capacitor C is discharged through siliconcontrolled rectifier Q, and squib 28. As a result, squib 28 is fired.

If the operator wishes to disarm the device he merely opens arm/disarmswitch 16. Capacitor C, will then discharge through resistor R andcapacitor C, will discharge through R, and transistor 0,, and resistorsR R3 and R5.

Many modifications and uses of the present invention, includingconstructing it of miniaturized components and installing it in thecap-well of the mine to be detonated, is contemplated by the inventorand is considered so disclosed.

What is claimed is:

l. A firing device for detonating a squib or other explosive devicewherein the fire control unit is remote from said explosive device,comprising:

a power supply for providing electric device;

an explosive charge;

explosive charge detonating means selectively coupled to said powersupply for firing said explosive charge, comprising electrical chargestorage means and an anti-disturbance firing mechanism;

fire controlling means remote from said explosive detonating means andsaid explosive charge for controlling the firing of said explosivecharge, comprising an operator actuated firing switch, arming anddisarming means coupled to one side of said power supply for arming anddisarming said explosive detonating means; a transistor, and a lamp thatwill light when said arming andl disarming means is in the arming modeand be extingished when said electrical charge storage means issufficiently charged to detonate said explosive charge, wherein oneterminal of said lamp is coupled to the first terminal of saidtransistor, said operator actuated firing switch is coupled between thesecond terminal of said transistor and the other terminal of said powerfor said ated firing switch is closed, when said coupling means isopencircuited, and when said coupling means is short-circuited.

3. The device of claim 2 wherein said detonating means further comprisesa silicon controlled rectifier connected in parallel to the combinationof of said explosive charge and the parallel combination of a resistorand said storage means.

1. A firing device for detonating a squib or other explosive devicewherein the fire control unit is remote from said explosive device,comprising: a power supply for providing electric power for said device;an explosive charge; explosive charge detonating means selectivelycoupled to said power supply for firing said explosive charge,comprising electrical charge storage means and an anti-disturbancefiring mechanism; fire controlling means remote from said explosivedetonating means and said explosive charge for controlling the firing ofsaid explosive charge, comprising an operator actuated firing switch,arming and disarming means coupled to one side of said power supply forarming and disarming said explosive detonating means; a transistor, anda lamp that will light when said arming and disarming means is in thearming mode and be extingished when said electrical charge storage meansis sufficiently charged to detonate said explosive charge, wherein oneterminal of said lamp is coupled to the first terminal of saidtransistor, said operator actuated firing switch is coupled between thesecond terminal of said transistor and the other terminal of said lamp,the junction of said lamp and said operator actuated firing switch iscoupled to said arming and disarming means, and the third terminal ofsaid transistor is coupled to the other side of said power supply. 2.The device of claim 1 wherein said fire controlling means is coupledthrough a coupling means to said detonating means such that aFter saiddetonating means is enabled said explosive charge will detonate whensaid detonating means is moved, when said operator actuated firingswitch is closed, when said coupling means is opencircuited, and whensaid coupling means is short-circuited.
 3. The device of claim 2 whereinsaid detonating means further comprises a silicon controlled rectifierconnected in parallel to the combination of of said explosive charge andthe parallel combination of a resistor and said storage means.